Optimize code

apache · Nov 12, 2020 · 68d3388 · 68d3388
1 parent 72ceacc
commit 68d3388
Show file tree

Hide file tree

Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala
@@ -813,7 +813,8 @@ object CollapseRepartition extends Rule[LogicalPlan] {
 object OptimizeWindowFunctions extends Rule[LogicalPlan] {
   def apply(plan: LogicalPlan): LogicalPlan = plan resolveExpressions {
     case we @ WindowExpression(AggregateExpression(first: First, _, _, _, _), spec)
-      if !spec.orderSpec.isEmpty =>
+      if spec.orderSpec.nonEmpty &&
+        spec.frameSpecification.asInstanceOf[SpecifiedWindowFrame].frameType == RowFrame =>
       we.copy(windowFunction = NthValue(first.child, Literal(1), first.ignoreNulls))
   }
 }

diff --git a/...src/test/scala/org/apache/spark/sql/catalyst/optimizer/OptimizeWindowFunctionsSuite.scala b/...src/test/scala/org/apache/spark/sql/catalyst/optimizer/OptimizeWindowFunctionsSuite.scala
@@ -36,7 +36,7 @@ class OptimizeWindowFunctionsSuite extends PlanTest {
   val b = testRelation.output(1)
   val c = testRelation.output(2)
 
-  test("replace first(col) by nth_value(col, 1) if the window frame is ordered") {
+  test("replace first(col) by nth_value(col, 1)") {
     val inputPlan = testRelation.select(
       WindowExpression(
         First(a, false).toAggregateExpression(),
@@ -52,6 +52,17 @@ class OptimizeWindowFunctionsSuite extends PlanTest {
     assert(optimized == correctAnswer)
   }
 
+  test("can't replace first(col) by nth_value(col, 1) if the window frame type is row") {
+    val inputPlan = testRelation.select(
+      WindowExpression(
+        First(a, false).toAggregateExpression(),
+        WindowSpecDefinition(b :: Nil, c.asc :: Nil,
+          SpecifiedWindowFrame(RangeFrame, UnboundedPreceding, CurrentRow))))
+
+    val optimized = Optimize.execute(inputPlan)
+    assert(optimized == inputPlan)
+  }
+
   test("can't replace first(col) by nth_value(col, 1) if the window frame isn't ordered") {
     val inputPlan = testRelation.select(
       WindowExpression(